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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
If you want an open-ear pair for running, cycling and all-day awareness, choose Monster Open Ear AC228; if you need tiny in-ear buds built for side sleepers and small ear canals, choose goazzzl Sleep Earbuds. These two are aimed at completely different moments in your day, and that's exactly why the decision is easier than it looks.
• Monster Open Ear AC228 — biggest strength: a clip-on open-ear design with 13mm dynamic drivers, Bluetooth 6.0 and directional audio that pushes sound toward your ear canal while keeping you aware of traffic and conversation.
• Monster Open Ear AC228 — biggest trade-off: open-ear means no noise blocking at all, and there's no noise control of any kind, so loud environments will fight your music.
• goazzzl Sleep Earbuds — biggest strength: an invisible, ultra-compact in-ear shape with soft silicone eartips designed specifically for sleeping, including side sleepers and small ear canals.
• goazzzl Sleep Earbuds — biggest trade-off: no battery figures are published, and the tiny sealed fit means you're cut off from your surroundings — fine at night, less ideal on a bike.
• Who should pick which: Monster for daytime movement and awareness; goazzzl for bedtime, travel and quiet focused listening.
The AC228 is a sport-first design. It clips onto your ear rather than plugging into it, and Monster builds it around a 13mm dynamic driver with a 20Hz–20,000Hz range — a full-range spec that suggests it can handle most genres without sounding thin. The interesting part is the directional audio approach: instead of blasting sound into open air and hoping for the best, the earbuds aim output toward your ear canal. In my opinion that's the right call for an open-ear product, because sound leakage is the number one complaint people have about this category.
Comfort engineering is where this one earns its keep. The frame uses skin-friendly liquid silicone paired with a flexible nickel-titanium memory alloy, which is the same family of material used in frames that need to bend and spring back without losing shape. Translation: it adapts to different ear shapes and resists falling off during movement. Combined with a lightweight build — the whole package is listed at 0.17 kg including the case and cable — this is a pair you can forget about mid-run.
Battery is straightforward: roughly 8 hours per charge, extended to about 24 hours with the charging case. Monster's own bullet points mention 30 hours of playtime in the title and 24 hours in the body, so I'd plan around the more conservative 24-hour figure with the case. Charging takes about 8 hours, which is slow by modern standards, so overnight charging is the sensible habit.
The IPX5 rating covers sweat, rain and heavy workouts, and Bluetooth 6.0 brings faster pairing and better stability than older versions — useful for gaming and calls where latency and dropouts matter.
Buy it if: you run, cycle, walk city streets or hike, and you want music without losing awareness of cars, dogs and people. Skip it if: you want to block out noise on a plane, in a noisy office, or in bed next to a snoring partner. There is no noise control here — that's the design, not a flaw.
The goazzzl pair solves a problem most earbuds ignore entirely: lying on your side with something in your ear. These are deliberately mini — an invisible, ergonomic shape intended to sit naturally inside the ear canal — and the whole pitch is discreet, low-profile comfort. Ultra-soft silicone eartips and caps create a snug but gentle seal, and goazzzl explicitly designs for side sleepers staying secure through the night.
The size angle matters more than it sounds. If you've ever had regular earbuds ache after twenty minutes, or pop out of narrow canals, "small ear canals" in the product name is doing real work here. This is a fit-first product, and fit is the single biggest reason sleep earbuds get returned.
Sound is described as clear and balanced, with an acoustic cavity design that helps reduce leakage for better privacy. Note the inclusion of Sound Isolation as the noise control method — that's passive sealing, not active cancellation, so it dulls the room rather than erasing it. That's exactly what you want at night: enough muffling to sleep, not so much that you can't hear an alarm.
Controls are touch-based for playback, volume, calls and voice assistants, and compatibility spans iOS, Android, Mac and most Bluetooth devices. One-step auto pairing means they reconnect to your last device the moment you lift them out of the case. IPX5 waterproofing carries over to workouts and travel too, so they're not strictly a bedside-only product.
The honest gap in the data: no battery life or charge time is published. If runtime matters to you, that's a question worth resolving before you commit.
Buy it if: you're a side sleeper, you have small ear canals, or you want buds so small they disappear for travel, naps and quiet listening. Skip it if: you need situational awareness outdoors or you want confirmed all-day battery numbers.
Side-by-Side: Which Should You Choose?
• Best for sleeping and side sleepers → goazzzl Sleep Earbuds. That's the entire design brief: soft silicone, minimal profile, secure through the night.
• Best for small ear canals → goazzzl Sleep Earbuds. Compact, invisible in-ear shape built for narrow canals.
• Best for battery certainty → Monster Open Ear AC228. Around 8 hours per charge and roughly 24 hours with the case, with Bluetooth 6.0.
• Best for staying aware of traffic and conversation → Monster Open Ear AC228. Open-ear by design; the goazzzl seals you in.
• Best for muffling a noisy room → goazzzl Sleep Earbuds. Passive sound isolation from the sealed silicone fit. The Monster has no noise control at all.
• Best for privacy without plugging in → Monster Open Ear AC228. Directional audio aims sound at your canal and limits leakage.
• Best for travel and quick pairing → goazzzl Sleep Earbuds. One-step auto pairing and a genuinely pocketable size.
• Best for hands-on control on both → a tie. Both use touch controls; the goazzzl adds volume and voice assistant access.
In my opinion, if you're buying one pair for the way most people actually use earbuds — moving around, sweating, needing to hear the world — the Monster Open Ear AC228 is the safer pick. The spec sheet is complete: driver size, frequency range, Bluetooth version, IPX5, and a battery figure you can plan around. The goazzzl Sleep Earbuds are the better answer for a narrower but very real job: side sleeping, small ear canals, and discreet in-ear listening, with the caveat that goazzzl doesn't publish battery life, so confirm that before buying. Buy the Monster for movement. Buy the goazzzl for bed.
Yes, in my opinion. The Monster is open-ear, so you keep awareness of traffic, and it uses a nickel-titanium memory alloy frame with liquid silicone to stay put. The goazzzl seals your canal, which works against you outdoors.
That's their main purpose. goazzzl designs them with ultra-soft silicone eartips and caps and states they stay secure for side sleepers, with a compact shape made for small ear canals.
Not published in the available product details. The Monster Open Ear AC228 lists about 8 hours per charge and roughly 24 hours with its case, so if runtime is a deciding factor, that's the more transparent option.
The Monster Open Ear AC228 has no noise control — it's designed for awareness. The goazzzl Sleep Earbuds list sound isolation, meaning passive sealing from the silicone fit, which reduces room noise rather than cancelling it electronically.
If price is the deciding factor, check the current price on Amazon for both — this page includes a button for that, and it's the only way to compare them fairly on cost.
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